The Definitive Evidence of a Plasma Copolymerization of Alkyl and Perfluorinated Acrylates Using High Resolution Mass Spectrometry and Mass Defect Analysis

Highlighting an actual plasma copolymerization remains difficult when using infrared or x-ray photoelectron spectroscopies as they provide no evidence of the formation of covalent bonds between the precursors. The combination of high resolution mass spectrometry and mass defect analysis is proposed to characterize plasma (co)polymers of alkyl and perfluorinated acrylates. The mass spectra of the coatings are readily turned into Kendrick mass defect plots unambiguously demonstrating the occurrence of plasma co-oligomers, as suspected from their thermal behavior. Requiring a proper calibration only, the mass defect analysis elegantly transforms an abstruse mass spectrum of plasma polymer in simple point series and constitutes a user-friendly method for data mining.